Aside from the amusing interactions between Niko Bellic and the women he dates, there can be several in-game benefits to starting a relationship with any of the datable characters. Putting in a little bit of time to raise the fondness of the girlfriends can unlock their "special abilities": these can help in particularly difficult missions late in the game.

Like the other relationships that Niko has with his friends in GTA IV, favor can be gained with girlfriends by taking them to different venues around the city. Unlike the male friends, however, dating is more than just worrying about the venue. To have a successful date Niko must cater to the women's tastes in three areas; clothing, vehicle, and how fancy the date is. Each woman has different tastes and will respond accordingly.

Reaching 100% fondness with all five girlfriends is not required to achieve 100% completion of the game.

The player will not be able to date Michelle anymore after the mission The Snow Storm

The player will not be able to date Kate anymore after the mission One Last Thing

Internet Girlfriends

After the mission Out of the Closet for Brucie Kibbutz, dates can be set up online through www.love-meet.net or www.craplist.net. 12-24 in-game hours after contacting the girl, she sends Niko an email. The date and time of the first date will be added to the organizer in Niko's phone. The first date is very important as it will determine whether or not the girlfriend will give Niko her phone number so he can continue dating her. If an Internet girlfriend's fondness is raised to a high enough level, her "special ability" is unlocked.

If Niko Bellic has a bad date or does not ask to come inside, the girl dumps Niko. However, wait a few in-game days and they reappear on the site so Niko can try again. When Niko meets a girlfriend again after being dumped or dumping her they will act as if they had never met him.

Ballad of Gay Tony

There are ten "girlfriends" that Luis Lopez can have in The Ballad of Gay Tony. Luis is able to dance with them in the clubs and if he does well they'll bring Luis to the restrooms for an encounter, after which they may give Luis their number. Afterwards, they can be contacted, or may contact Luis, for a "booty call". There are ten Luis "girlfriends" including:

Damageproofing Vehicles

A glitch in the game can make any vehicle damage proof by scaring Niko's date right when she gets in the car (however these properties can randomly disappear at any time). To do the trick, fire a weapon when Niko's date gets in the car (wait for both door-opening and seating animations to pass). With a helicopter, snap off the blades at a height where Niko's girlfriend can get hurt but won't die.

One-handed Driving

Another glitch in the game will make Niko drive one-handed if he says goodbye after a successful date instead of asking to come inside. Niko's right arm will be at his side, usually clipping through parts of the car in between the seats. To rectify this, make Niko call someone or get out and back in the car.